Electronic systems often incorporate a semiconductor package (e.g., including a semiconductor die) that generates significant thermal energy. System designers spend considerable effort to provide sufficient heat dissipation capability in such systems by providing a thermally conductive path from the semiconductor package to a heat sink. The heat sink may for example be a ventilated conductive plate or an active device such as a thermoelectric cooler.
Certain difficulties arise when these electronic systems utilize multiple dies and other heat-generating devices. More particularly, each die and device must have its own heat dissipation capability; this for example complicates system design by requiring adequate ventilation and/or thermally conductive paths and heat sinks for the entire system. Such ventilation, thermal paths and heat sinks increase cost and complexity, among other negative factors.
Certain difficulties also arise in multiple die electronic systems because of mechanical tolerance build-up. That is, the physical mounting of multiple dies on a printed circuit board (PCB), for example, results in certain minute misalignment between reference surfaces intended to be co-aligned. Accordingly, any attempt to use a common heat sink must also accommodate the tolerance build-up to ensure appropriate thermal transfer across the physical interface. Tolerance build-up may for example occur due to the soldering that couples the dies to the PCB, and/or due to manufacturing inconsistencies in the rigid covers or “lids” which sometimes cover individual dies. In any event, a thermal sink coupled to multiple dies should account for these tolerance issues at the interface between the sink and the multiple dies in order to properly dissipate generated thermal energy. Designers of the prior art thus often over-compensate the thermal design to accommodate worst-case interface tolerance issues. Once again, this increases cost and complexity in the overall electronic system, among other negative factors.